The present invention relates generally to a pressure controller and, more particularly, to an electromagnetically operated pressure controller.
Conventional pressure controllers are disclosed in Laid-Open Japanese Utility Model Applications Nos. 52509/1985 and 52510/1985. Those applications relate to structures for providing concentricity between an electromagnetic coil and a plunger. As disclosed, a shaft on a plunger is supported by bearings on a core of an electromagnetic coil. However, this prior art structure entails a complex and expensive construction. Specifically, the machining precision required of the bearing portion significantly increases the cost of the device.
The object of the present invention, therefore, is to provide an improved pressure controller that is simple in construction and in which an electromagnetic plunger and a valve spindle driven thereby may be assembled on a solenoid with high accuracy and concentricity.